The Magical Number Seven, Plus or Minus Two

Details

Photo

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Name

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Authors

George A. Miller

Year

1956

Field

Cognitive psychology

Why it stuck

Classic on working memory limits; that “7 ± 2” rule explains why I forget set plays if we add more than three options (and why cluttered dashboards make my brain tap out).

My take

I use this as my hard cap for how many KPIs belong on a single slide; anything beyond nine metrics and I assume the audience is already thinking about lunch.